tda8000t NXP Semiconductors, tda8000t Datasheet - Page 16

• Manufacturer Part Number: tda8000t
• Description: Smart Card Interface
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Notes
1. START, WRITE, CLKDIV and PRES are active LOW; RSTIN and PRES are active HIGH.
2. The transition time and duty factor definitions are shown in Fig.12;
3. P is the card programming voltage set by pins PSEL1 and PSEL2.
4. This condition ensures correct start-up of the oscillator with crystals having series resistance up to 100 .
5. The path between I/O and I/O( C) is as follows (see Fig.13):
1996 Dec 12
handbook, full pagewidth
t
t
t
SYMBOL
5
st
d(clk)
Smart card interface
a) Clamp to V
b) 20 k pull-up resistor to V
c) Two opposite npn transistors with sensing pnp transistor.
d) Clamp to V
e) The base current of the npn transistor is decreasing when their collector current increases. This means the
voltage drop is very low for small currents and becomes maximum for some mA. Thus V
current limits, and high impedance feature. The output current from I/O and I/O( C) when the line is open-circuit
is the sum of the pull-up current and the base currents.
end of the window for sending CLK
to the card
maximum pulse width on START
before V
delay between RSTIN and CLK
CC
SUP
.
CC
; thus V
PARAMETER
starts rising
10%
t r
OH
90%
on I/O( C).
CC
; thus V
t 1
Fig.12 Definition of transition times.
OH
on I/O.
see Fig.6
see Fig.6
CONDITIONS
90%
t f
16
10%
t 2
=
-------------- -
t
160
1
t
+
1
t
MIN.
2
.
TDA8000; TDA8000T
MBH856
TYP.
OL
V OH
1.5 V
V OL
Product specification
on I/O and I/O( C),
30
2
MAX.
UNIT
s
s
s